Tunnel-kiln



P. DH. DRESSLER.

TUNNEL KILN.

APPLICATION FILED DEC. 17, 1919.

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P. DH. DRESSLER.

TUNNEL KILN. APPLICATION FILED 050.17. I9I9.

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Patented Jan. 25,1921.

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TUNNEL KILN.

APPLICATION FILED 050.17, 1919.

UNITED STATES PATENT OFFICE.

l PHILIP DH. DRESSLER, OF ZANESVILLE, OHIO, ASSIGNOR TO AMERICAN DRESSLER TUNNEL KILNS, INC., OF NEW YORK, N. Y., .A CORPORATION OF NEW YORK.

TUNNEL-KILN.

Application led December-17', 1919.

T 0 all w hom t may concern Be it known that I, PHILIP DH. DREssLnR,

y air preheating conduits of an elongated tunnel kiln.

The general object of my present invention is to provide simple and effective means for supplying air to support combustion to a pluralityv of burners located in the combustion chambers. at intervals along the length of the latter after preheating this air by drawing it through heat absorbing pipes in the cooling off Zone of the kiln whereby the air `forms a mediumfor abstracting heat from the goods carrier prior to their discharge from the kiln and at the Same time is effectively preheated.

The various features of novelty which characterize my invention are pointed out with particularity in the claims annexed to and forming a part of this specification. For a better understanding of the invention, however, and the advantagespossessed by it reference should be had to the accompanying drawings and descriptive matter in which I have illustrated and described a preferred embodiment of the invention.

Of the drawings: Figure 1 is a somewhat diagrammatic elevation of a kiln;

Fig. 2 is a plan of a portion of the'kiln in section on the line 2 2 of Fig. 3;

Fig. 3 is a transverse section onthe line 3 3 of Fig. 2;

Fig. 4 is a partial transverse section on the line 4 4 of Fig. 2;

Fig. 5 yisa partial transverse section on the line 5 5 of Figl 2;

Fig. 6 is a partial section on the line 6 6 of Fig. 2;

Fig. 7 is a partial section on the line 7 7 of Fig. 6;

Fig. 8 is a partial section on the line 8 8 of Fig. 1; and

Specification of Letters Patent.

Fig. 9 is a partial section on the line 9 9 of Fig. 1.

In the drawings I have illustrated the use of my invention in a tunnel kiln of the well-known Dressler type in which the kiln chamber Avproper is inclosed by the -usual refractory wall B, and has lateral inlet and egress doors C and D respectively at the opposite ends of the kiln.

Adjacent the exit end of the kiln on the benches B at the sides of the pathway B2 for the goods carrying cars, are located pipes H, see Figs. 1 and 9,. through which air is passed to thereby preheat the air and at the same time abstract the heat from the goodsand cars as the latter'move from thehigh temperature zone of the kiln through the rcooling olf zone in which the pipes H are The partially cooled products of combustion pass through the pipes F to an exit tunnel G leading to a stack or other draft creating device. Air preheated by its passage through the pipes H, and combustible gas are introduced into the combustion chambers at the ends of the latter adjacent the cooling off zone of the kiln. Inso far as above described in detail the apparatus shown is a typical Dressler kiln possessing nothing now novel with me.

From each of the two headers I-I, one at each side of the kiln to which the corresponding groups of pipes H are connected, a conduit or passage J leads downward in the masonry substructure of the kiln to a cross conduit J. A passage JA. leading upward from the cross channel J at the side of the KA to a cross passage K formed in the masonry substructure ofthe kiln and connected to a tunnel K which extends longitudinally of the kiln beneath the pathway B2 for the goods carrier. At intervals the tunnel K is provided with lateral branches l-Kw (see Fig. 4) each having at its end an uprising extension K11. Flow through each conduit I 11 is controlled by a corresponding -sliding damper M (see Figs. 6 and 7) having an operating extension M2 which is located in a tunnel or passageway M* provided for the p urpose and leading to the exterior of member Ll is provided with a grid or apertured plate L3 so that the air passing from the passage L into the combustion cha-mb'er proper is discharged in a. plurality of comparatively small streams. Each member L is formed with a second passage L2 `which extends at an angle to the passage and communicates -with the corresponding gas supply passa-ge O13.

The gas supply passages O13, of' which there is one for each burner, each extend transversely of the kiln to the adjacent youter side of thelatter and each contains a sliding damper MA regulating the iniiux of gas into the passage O13 through a port O12 from va corresponding gas supply conduit O10 or O11 running longitudinally of the kiln. The gas supply conduit O10 is at the right side of the kiln and the conduit O11 is at the left hand side of the kiln.

` The two gas supply conduits O10 and O11 Aing the pressure in the two are supplied with gas through conduit extensions 05- and O, respectively, from a common gas supply pipe O. The gas supply conduits O10 and O11 are connected at their ends remote from the supply pipe O to a cross passage O14 with a normally closed outlet O15 at the exterior of the kiln. The purpose of this connection is to v:facilitate the burning out of the conduits to remove carbon deposits and the like from time to time. In regular normal operation the cross passage O14 and outlet O15 perform no function other than that of equalizgas supply conduits 01 and O11.

The tunnel K is provided at its end remote from the passages KA and K' with lateral branches K20. These have vertical lextensions K21 which communicate with ducts K2? leading to the exterior of the kiln and controlled by dampers MB. The hot air leaving *the kiln through the passages l 22 may be passed directly to a stack discharging into the atmosphere or may be utilized for any purpose for which this hot air is suitable. The passages K2". K21 and *KN form a convenient means for'disposing of air which it may be desirable to ypass for goods heating purposes through the pipes H in the cooling off zone of the kiln, in excess of the` amount actually required to support combustion in the combustion. chambers E under certain conditions.

As shown, each combustion chamber E is formed for thel most part of tile sections formed with Ventilating passages therein, such as are commonly employed in Dressler kilns, special bottom sections LE being provided at each burner into eachof which the open upper end of 'the corresponding burner member L enters. E10 represents a refractory head or shield projecting over the corresponding burner member L thus preventing the air and gas entering the combustion chamber from that burner member mingling, prior to combustion, with the -products of combustion introduced into the ing p ipes H of thevcooling off Zone all or" the air which is necessary or desirable to effect the desired cooling of the goods and goods carrying cars in passing through the cooling orf zone, even though the air required for this purpose is-in excess lof that required to support combustion. An important characteristic 'of the apparatus shown are the provisions for obtaining the proper movements of air andgas through the various conduits and passages of the entire chamber without creating pressure diierentials at any one point large enough to produce appreciable leakage from the combustion chambers into the kiln chamber proper. or from the latter into t-he combustion chambers.

By using a `stack or exhauster to create asuction at the outlet end of the combus` tion chambers, and a fan or blower at the opposite end ofv the combustion chambers, the frictional resistance to the flow of air and products of combustion may be overcome with a maximum difference between the pressure in the combustion chambers and the about half thatk which would be required if the How through the combustion chambers were wholly due to suction at one end or pressure at the other end of each combustion chamber. The special arrangement shown in which the fan or blower S is placed between the air inlets to the combustion chambers and the outlets from the pipes H makes it possible to secure a desirable air pressure at the combustion chamber linlets while maintaining a prespressure of the atmosphere only.

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sure in the pipes H low enough to substan- V tially minimize leakage through the joints of those pipes.

portions of the combustion chambers with the air and gas inlet provisions thereto disclosed but not specifically claimed herein.

p While in accordance with the provisions of the statutes I have illustrated and described the best form of my invention now known to me it will be apparent to those skilled in the art that changes may be made in the form of the apparatus disclosed herein without departing from the spirit of my invention as set forth in the appended claims and that certain features of my invention may sometimes be used to advantage without'a correspondinguse of other features.

Having now described my invention, what I claim as new and desire to secure by Letters Patent, is:

1. In a tunnel kiln having an elongated kiln chamber comprising a heating zone and a goods cooling zone at one end of the heating zone, and having an air preheating and goods' cooling conduit extending along the cooling zone, and a combustion chamber separated by a heat conducting wall from the kiln chamber extending along the heating zone thereof, the improvement which consists in a fan or blower having its inlet connected to the cooling zone conduit and its outlet connected to the combustion chamber whereby pressure differentials tending toy '2. In a tunnel kiln havingvan elongated' .kiln chamber comprising a heating zone and a vgoods cooling zone at one end of the heat-y ing Vzone and having an air heating and goods 4cooling conduit extending along the cooling zone and aicombustion chamber extending along the heating zone, the improvement which consists in a fan for drawing air through said conduit and delivering a'portion of said air to said combustion chamber vand provisions for diverting a portion of chamber comprising a heating zone and a goods cooling zoneat one end ofthe heating zone, and having an air preheating and I goods cooling chamber separated by a heat A conducting wall from the kiln chamber extending along the heating zone thereof,'the improvement which consists in theucombination of a suction device for drawing products of combustion out of the combustionl heating conduit and into 'the combustion ling and goods cooling conduit extending along the cooling zone, and a combustion chamber separated by a heat conducting wall from the kiln chamber extending along the heating zone thereof, the improvement which consists in a fan or blower having its inlet connected to the cooling Zone conduit and its outlet connected to the combustion chamber at the adjacent ends of said chainberl and cooling zone conduit, and in combination therewith a suction device for drawing products of combustion out of the combustion chamber whereby pressure differentials tending to create leakage iiow between said kiln chamber and said coinbustion chambers o'r conduit may be minimized.

5. In a tunnel kiln having an elongated kiln chamber with longitudinal benches therein at opposite sides of a pathway for goods carrying means and comprising a heating Zone and a goods cooling zone at one end of the heating zone and having combustion cham-bers mounted on said benches in the heating zone and air preheating and goods cooling conduits mounted on the benches in the cooling zone, the improvement which consists in a conduit system. connecting said goods cooling conduits to said combustion chambers comprising a portion located be` neath said pathway in the heating zone with i lateral'butlet branches extending upward through the benches and opening to the combustion chambers at intervals along the length of the latter.

6. In atunnelkiln having an elongated kiln chamber with longitudinal benches therein at opposite sides of a pathway for goods carrying means and comprising a heating zone and a goods cooling Zone at one end of the heating zone and having combustion chambers mounted on said benches in the heating zone and air preheating and goods cooling conduits mounted on the benches in thev cooling zone, the improvement which consists in a conduit system connecting saidgoods cooling conduits to said Acombustion chambers comprising a portion located beneath said pathway in the heating zone with lateral-outlet branches extending upward through the -benches and opening to the combustion chambers at intervals along the'length of the latter, and means for separately regulating the discharge through the difei-ent outlet branches of said conduit system.

7. Ina tunnel kiln having an elongated kiln chamber with longitudinal benches llO laoV

therein at opposite sides of a pathway for goods carrying means and comprising a heating zone and a goods cooling zone at one end of the heating zone and having combustion chambers mounted on said benches in the heating zone and air preheating and goods cooling conduits mounted on the benches in the cooling zone, the improvement which consists in a conduit system for delivering air preheated in the cooling zone" conduits to said combustion chambers lat multiple points along the length of each and for supplying combustible gas to the cornbustion chambers at the same points, comprising a conduit located beneath the pathway for the goods having lateral outlets opening through the benches to the combustion chambers,` and a pair of conduits located a-t the outer side of the two benches and each having lateral outlets opening through the benches to Athe combustion chamber. y

8. In a tunnel kiln having an elongated kiln chamber with longitudinal benches therein at opposite sides ofy a pathway for goods carrying means and comprising a heating zone and a goods cooling zone at one end of the heating zone and having combustion chambers mounted on said benches 1n the heating zone and air prehe'ating and `goods cooling conduits mounted on the benches in the cooling zone, the improvement which consists in a conduit system for delivering air preheated in the cooling zone conduits to said combustion chambers at multiple points along the length of each and 'for supplying combustible gas to the combustion chambers at the same points, comprising a conduit located beneath thepathway for the goods having lateral outlets opening'through the benches to the combustion chambers, and a pair of conduits located at the outer side of the two benches, each khaving lateral outlets opening through the benches to the combustion chamber, and means for separately regulating the discharge through each of 'said outlets.

9. In a tunnel kiln having an elongated kiln chamber with longitudinal benches therein at opposite sides of a pathway 'for goods carrying means and comprising a heating zone and a goods cooling zone at one end of the heatmg Zone, and having combustion chambers mounted on said benches in the heating Zone and air' preheating and goods cooling conduits mounted on the benches in the cooling Zone, the improvement which consists in a conduit system ,comprising a portion located beneath said pathway in the heating Zone. with lateral outlet branches extending upward through the-benches and opening tothe com-vV bustion chambers at intervals along the j length. of the latter and in combination therewith'A a vfan or blower drawing air through said goods cooling conduits and delivering -it to said portion of said conduit system.

l0. In a tunnel -kiln having an elongated kiln chamber lwith longitudinal benches therein at opposite sides ofv a pathway for goods carrying means and comprising a heating zone' and a goods cooling zone at `goods cooling conduits and delivering it to said portion ofy said conduit system, said conduit system portion having an outlet for fair drawn through said cooling conduits in excess of the amount required in said combustion chambers.

Signed at Zanesville, in the county of Muskin um and State of Ohio this 13th day of ecember A. I). 1919.

, PHILIP DH. DRESSLER. 

